According to data in “Global Drowning Report: Preventing a Main Killer” of World Health Organization in 2014, drowning is one of top ten main death causes of children and youths in various regions. In total, 372,000 people are died of drowning every year, of which more than half of the people died of drowning are less than 25 years old.
A lifesaving device in a related art needs to be actively opened by a user. Obviously, after the user loses consciousness because of drowning, the lifesaving device cannot be made to work, and thus there is danger, which urgently needs to be solved.